Surface-bound C3 on platelet-leukocyte complexes induced by Stx2, Stx1, Stx1B, O157LPS, and/or O111LPS. Incubation of whole blood with Stx2, Stx1, Stx1B, or O157LPS induced C3 deposition on platelet-monocyte (A) and platelet-neutrophil (B) complexes and a lesser increase of C3 on unbound monocytes (C) and unbound neutrophils (D). Data are expressed as box-plots depicting the median and range regarding the percentage of the platelet-monocyte or platelet-neutrophil population or the percentage of unbound monocytes or neutrophils that were positive for C3 (n = 12 experiments). The horizontal line within each box represents the median. The upper and lower limits of the box represent the interquartile range. The lower and upper limits represent the range. C3 deposition on complexes or on unbound monocytes or neutrophils in whole blood incubated with an agonist was compared with PBS-treated whole blood. *P < .05; **P < .01; ***P < .001. NS indicates not significant.